Don't attempt to restart non-resettable actors

environment.go

@@ -236,8 +236,9 @@ func (this *environment) start(actor Actor) {
 	go this.run(actor)
 }
 
-// run runs the given actor, restarting it if it fails. This function will exit
-// when the actor's context is canceled. The actor will be removed from the
+// run runs the given actor. This function will exit
+// when the actor's context is canceled, or the actor has stopped or exited.
+// The actor will be removed from the
 // environment once this function exits, and the environment's wait group
 // counter will be decremented. note that this function will never increment the
 // wait group counter, so start should usually be used instead.
@@ -349,6 +350,13 @@ func (this *environment) runRunnable(ctx context.Context, actor Runnable) (stopE
 			if this.flags.crashOnError {
 				panic(fmt.Sprint(err))
 			}
+
+			// if an actor isn't resettable, don't reset
+			// or restart it
+			if _, ok := actor.(Resettable); !ok {
+				stopErr = err
+				return
+			}
 		}
 
 		// restart logic
@@ -373,7 +381,8 @@ func (this *environment) runRunnable(ctx context.Context, actor Runnable) (stopE
 			restartInterval = restartInitialInterval
 		}
 
-		// reset if needed
+		// reset if needed. this condition will always be true because
+		// this code path is restricted to Resettable anyway
 		if actor, ok := actor.(Resettable); ok {
 			if this.Verb() { log.Printf("... [%s] resetting", typ) }
 			func() {

run.go

@@ -52,8 +52,8 @@ var env environment
 //   
 //   70. Running: Actors which implement [Runnable] or [RunShutdownable] are
 //       run, each in their own goroutine. The environment is able to restart
-//       actors which have failed, which entails resetting the actor if it
-//       implements [Resettable], and running the actor again within the same
+//       actors which have failed if they implement [Resettable], which entails
+//       resetting the actor and running it again within the same
 //       goroutine. If an actor does not run for a meaningful amount of time
 //       after resetting/initialization before failing, it is considered erratic
 //       and further attempts to restart it will be spaced by a limited,